Folders

Available since Basecamp 5: folders group projects together on a person's home screen. Folders are per-user — each person arranges their own home into folders, and filing a project into a folder for yourself doesn't change how anyone else sees it. Membership, ordering, and appearance all belong to the authenticated user.

For historical reasons the path and the wire type say stack(s) rather than folder(s); they are the same thing.

Endpoints:

• Get folders
• Get a folder
• Create a folder
• Update a folder
• Delete a folder

Get folders

• GET /stacks.json returns the authenticated user's folders, in the order they appear on the home screen.

Example JSON Response

[
  {
    "id": 2085958513,
    "name": "Client work",
    "type": "Stack",
    "created_at": "2026-07-27T10:16:49.312Z",
    "updated_at": "2026-07-27T10:16:49.325Z",
    "bucket_ids": [],
    "is_emoji_only_name": false,
    "star_url": "https://3.basecampapi.com/195539477/buckets/2085958513/stars.json",
    "gauges_url": null,
    "color": null,
    "image_url": null,
    "url": "https://3.basecampapi.com/195539477/stacks/2085958513.json"
  }
]

Copy as cURL

curl -s -H "Authorization: Bearer $ACCESS_TOKEN" https://3.basecampapi.com/$ACCOUNT_ID/stacks.json

Get a folder

• GET /stacks/2.json returns the folder with an ID of 2, including the projects grouped inside it under projects.

Example JSON Response

{
  "id": 2085958513,
  "name": "Client work",
  "type": "Stack",
  "created_at": "2026-07-27T10:16:49.312Z",
  "updated_at": "2026-07-27T10:16:49.325Z",
  "bucket_ids": [],
  "is_emoji_only_name": false,
  "star_url": "https://3.basecampapi.com/195539477/buckets/2085958513/stars.json",
  "gauges_url": null,
  "color": null,
  "image_url": null,
  "url": "https://3.basecampapi.com/195539477/stacks/2085958513.json",
  "projects": []
}

Copy as cURL

curl -s -H "Authorization: Bearer $ACCESS_TOKEN" https://3.basecampapi.com/$ACCOUNT_ID/stacks/2.json

Create a folder

• POST /stacks.json creates a new folder for the authenticated user and files the given projects into it. The folder is placed at the top of the home screen.

Optional parameters

Param	Type	Description
name	String	The folder's name. Defaults to New folder when blank or omitted.
project_ids	Array	IDs of the projects to file into the folder — the same ids the folder reports back as bucket_ids. Each must be a project the user can access, or an all-access project they're eligible to join — filing an all-access project the user isn't yet a member of also grants them access to it. Archived, trashed, or invitation-only projects the user isn't on are rejected: the whole request returns 404 Not Found and nothing is created. Omit it, or send null or an empty array, for an empty folder.

Example JSON Request

{
  "name": "Client work",
  "project_ids": []
}

A successful create returns 201 Created with the new folder's JSON shape, including its grouped projects:

Example JSON Response

{
  "id": 2085958513,
  "name": "Client work",
  "type": "Stack",
  "created_at": "2026-07-27T10:16:49.312Z",
  "updated_at": "2026-07-27T10:16:49.325Z",
  "bucket_ids": [],
  "is_emoji_only_name": false,
  "star_url": "https://3.basecampapi.com/195539477/buckets/2085958513/stars.json",
  "gauges_url": null,
  "color": null,
  "image_url": null,
  "url": "https://3.basecampapi.com/195539477/stacks/2085958513.json",
  "projects": []
}

Copy as cURL

curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/json" \
  -d '{"name":"Client work","project_ids":[]}' \
  https://3.basecampapi.com/$ACCOUNT_ID/stacks.json

Update a folder

• PUT /stacks/2.json renames the folder with an ID of 2. Only name can be changed; a folder's projects, ordering, and image are managed elsewhere.

Permitted parameters

Param	Type	Description
name	String	The folder's new name.

Example JSON Request

{
  "name": "Active client work"
}

Returns 200 OK with the updated folder's JSON shape:

Example JSON Response

{
  "id": 2085958513,
  "name": "Active client work",
  "type": "Stack",
  "created_at": "2026-07-27T10:16:49.312Z",
  "updated_at": "2026-07-27T10:16:50.464Z",
  "bucket_ids": [],
  "is_emoji_only_name": false,
  "star_url": "https://3.basecampapi.com/195539477/buckets/2085958513/stars.json",
  "gauges_url": null,
  "color": null,
  "image_url": null,
  "url": "https://3.basecampapi.com/195539477/stacks/2085958513.json",
  "projects": []
}

Copy as cURL

curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -H "Content-Type: application/json" \
  -d '{"name":"Active client work"}' -X PUT \
  https://3.basecampapi.com/$ACCOUNT_ID/stacks/2.json

Delete a folder

• DELETE /stacks/2.json deletes the folder with an ID of 2 and returns 204 No Content. Deleting a folder unpins its projects from the person's home screen — the projects themselves are not deleted, and they are not moved back out onto the home screen; they simply stop appearing there until pinned again.

Copy as cURL

curl -s -H "Authorization: Bearer $ACCESS_TOKEN" -X DELETE \
  https://3.basecampapi.com/$ACCOUNT_ID/stacks/2.json